Password Leak Detection is an experimental feature in Chrome 78. It checks a given password against public databases of data breaches, in case of its use in a known security incident. Should this test prove positive, Chrome then offers a pop-up advising the user to change the password for the site or service in question.
https://www.notebookcheck.net/Chrome-may-soon-be-able-to-alert-the-user-if-their-passwords-have-been-stolen.431858.0.html